Thrombin:
Vasospasm may be caused in part by thrombin, according to some research (Zhang et al., 2001). Serine protease thrombin helps the coagulation process by degrading fibrinogen and generating fibrin. Before, Argatroban was discovered to improve neurological outcomes by reducing BBB rupture and brain edema, as well as having anti-cell death and anti-inflammatory effects that correspond to early brain injury after SAH (Sugawara, Jadhav, Ayer, Chen, Suzuki & Zhang, 2009). The discovery that thrombin has a role in a wide range of CNS pathologies suggests a therapeutic breakthrough (Krenzlin, Lorenz, Danckwardt, Kempski & Alessandri, 2016). Evidence from both in vivo and in vitro experiments showed that high levels of thrombin in the brain parenchyma can be harmful (Buisson, Nicole, Docagne, Sartelet, Mackenzie & Vivien, 1998; Jiang, Wu, Keep, Hua, Hoff & Xi, 2002; Lee, Drury, Vitarbo & Hoff, 1997; Vu, Hung, Wheaton & Coughlin, 1991; Xi, Keep, Hua, Xiang & Hoff, 1999). Thrombin, which also leads to ischemic brain injury, causes early brain edema after intracerebral hemorrhage (Lee, Drury, Vitarbo & Hoff, 1997; Vu, Hung, Wheaton & Coughlin, 1991). As a result, the role of thrombin activation in the pathophysiology of SAH is yet unknown.